| crystallization and preliminary crystallographic analysis of a thermostable family 52 beta-d-xylosidase from geobacillus stearothermophilus t-6. | beta-d-xylosidases (ec 3.2.1.37) are hemicellulases that hydrolyze short xylooligosaccharides into single xylose units. in this study, the first crystallization and preliminary x-ray analysis of a family 52 glycoside hydrolase, the beta-d-xylosidase (xynb2) from geobacillus stearothermophilus t-6, is described. xynb2 is a dimeric protein consisting of two identical subunits of 705 amino acids with a calculated molecular weight of 79 894 da. xynb2 was crystallized by the hanging-drop vapour-diffu ... | 2004 | 15272177 |
| insights into the dna repair process by the formamidopyrimidine-dna glycosylase investigated by molecular dynamics. | formamidopyrimidine-dna glycosylase (fpg) identifies and removes 8-oxoguanine from dna. all of the x-ray structures of fpg complexed to an abasic site containing dna exhibit a common disordered region present in the c-terminal domain of the enzyme. however, this region is believed to be involved in the damaged base binding site when the initial protein/dna complex is formed. the dynamic behavior of the disordered polypeptide (named loop) in relation to the supposed scenario for the dna repair me ... | 2004 | 15273302 |
| the c-terminal domain of dimeric serine hydroxymethyltransferase plays a key role in stabilization of the quaternary structure and cooperative unfolding of protein: domain swapping studies with enzymes having high sequence identity. | the serine hydroxymethyltransferase from bacillus subtilis (bsshmt) and b. stearothermophilus (bstshmt) are both homodimers and share approximately 77% sequence identity; however, they show very different thermal stabilities and unfolding pathways. for investigating the role of n- and c-terminal domains in stability and unfolding of dimeric shmts, we have swapped the structural domains between bs- and bstshmt and generated the two novel chimeric proteins bsbstc and bstbsc, respectively. the chim ... | 2004 | 15273312 |
| modulation of dna conformations through the formation of alternative high-order hu-dna complexes. | hu is an abundant, highly conserved protein associated with the bacterial chromosome. it belongs to a small class of proteins that includes the eukaryotic proteins tbp, sry, hmg-i and lef-i, which bind to dna non-specifically at the minor groove. hu plays important roles as an accessory architectural factor in a variety of bacterial cellular processes such as dna compaction, replication, transposition, recombination and gene regulation. in an attempt to unravel the role this protein plays in sha ... | 2004 | 15276833 |
| mapping glycoside hydrolase substrate subsites by isothermal titration calorimetry. | relating thermodynamic parameters to structural and biochemical data allows a better understanding of substrate binding and its contribution to catalysis. the analysis of the binding of carbohydrates to proteins or enzymes is a special challenge because of the multiple interactions and forces involved. isothermal titration calorimetry (itc) provides a direct measure of binding enthalpy (deltaha) and allows the determination of the binding constant (free energy), entropy, and stoichiometry. in th ... | 2004 | 15277671 |
| cloning and characterization of the catabolite control protein a gene from bacillus stearothermophilus no. 236. | the gene encoding the catabolite control protein a (ccpa) of bacillus stearothermophilus no. 236, a strong xylanolytic bacterium, was cloned, sequenced, and expressed in escherichia coli. the nucleotide sequence of the ccpa gene corresponded to an open reading frame of 1,005 bp that encodes a polypeptide of 334 amino acid residues with a calculated molecular mass of 36,902 kda. the ccpa protein belonging to the laci/galr family of transcriptional regulators was produced by a recombinant e. coli ... | 2004 | 15277745 |
| impact of protein flexibility on hydride-transfer parameters in thermophilic and psychrophilic alcohol dehydrogenases. | the hydride transfer catalyzed by thermophilic alcohol dehydrogenase (htadh) exhibits sharply different kinetic and activation parameters from that catalyzed by the more flexible psychrophilic alcohol dehydrogenase (psadh). in addition, the hydride transfer in htadh is affected by mutating two distal residues that are suggested to be responsible for the decreased local protein flexibility in htadh. these observations provide support for the view that protein dynamics is tightly coupled to the hy ... | 2004 | 15291528 |
| structural basis for template-independent rna polymerization. | the 3'-terminal cca nucleotide sequence (positions 74-76) of transfer rna is essential for amino acid attachment and interaction with the ribosome during protein synthesis. the cca sequence is synthesized de novo and/or repaired by a template-independent rna polymerase, 'cca-adding enzyme', using ctp and atp as substrates. despite structural and biochemical studies, the mechanism by which the cca-adding enzyme synthesizes the defined sequence without a nucleic acid template remains elusive. here ... | 2004 | 15295603 |
| biochemical characterization of a thermostable cysteine synthase from geobacillus stearothermophilus v. | the cysk gene encoding a cysteine synthase of geobacillus stearothermophilus v was overexpressed in e. coli and the recombinant protein was purified and characterized. the enzyme is a thermostable homodimer (32 kda/monomer) belonging to the beta family of pyridoxal phosphate (plp)-dependent enzymes. uv-visible spectra showed absorption bands at 279 and 410 nm. the band at 279 nm is due to tyrosine residues as the enzyme lacks tryptophan. the 410 nm band represents absorption of the coenzyme boun ... | 2004 | 15308337 |
| thermoactive extracellular proteases of geobacillus caldoproteolyticus, sp. nov., from sewage sludge. | a proteolytic thermophilic bacterial strain, designated as strain sf03, was isolated from sewage sludge in singapore. strain sf03 is a strictly aerobic, gram stain-positive, catalase-positive, oxidase-positive, and endospore-forming rod. it grows at temperatures ranging from 35 to 65 degrees c, ph ranging from 6.0 to 9.0, and salinities ranging from 0 to 2.5%. phylogenetic analyses revealed that strain sf03 was most similar to saccharococcus thermophilus, geobacillus caldoxylosilyticus, and g. t ... | 2004 | 15322950 |
| covalent reaction intermediate revealed in crystal structure of the geobacillus stearothermophilus carboxylesterase est30. | est30 is a thermophilic carboxylesterase cloned from geobacillus stearothermophilus that showed optimal hydrolysis of esters with short acyl chains at 70 degrees c. est30 is a member of a new family of carboxylesterases with representatives in other gram-positive bacteria. the crystal structure has been determined at 1.63a resolution using multiple anomalous dispersion data. the two-domain crystal structure showed a large domain with a modified alpha/beta hydrolase core including a seven, rather ... | 2004 | 15327954 |
| manual versus automated methods for cleaning reusable accessory devices used for minimally invasive surgical procedures. | we undertook a simulated-use study using quantitative methods to evaluate the cleaning efficacy of ported and non-ported accessory devices used in minimally invasive surgery. we chose laparoscopic scissors and forceps to represent worst-case devices which were inoculated with artificial test soil containing 10(6) cfu/ml enterococcus faecalis and geobacillus stearothermophilus and allowed to dry for 1 h. cleaning was performed manually, as well as by the automated si-auto narrow lumen cleaner. ma ... | 2004 | 15350714 |
| synthesis of polyhydroxylated piperidines and evaluation as glycosidase inhibitors. | a series of 16 new chiral nonracemic polyhydroxylated piperidines was synthesized utilizing several chiral beta-amino-alcohols. they act as a nitrogen source, chirality inducer and iminium stabilizer, in the desymmetrization of meso-trihydroxylated glutaraldehyde. the biological activity of these compounds towards several glycosidases (alpha-d-glucosidase, alpha-d-mannosidase, alpha-l-fucosidase) has been evaluated. | 2004 | 15351392 |
| x-ray crystal structure of ornithine acetyltransferase from the clavulanic acid biosynthesis gene cluster. | the orf6 gene from the clavulanic acid biosynthesis gene cluster encodes an oat (ornithine acetyltransferase). similar to other oats the enzyme has been shown to catalyse the reversible transfer of an acetyl group from n-acetylornithine to glutamate. oats are ntn (n-terminal nucleophile) enzymes, but are distinct from the better-characterized ntn hydrolase enzymes as they catalyse acetyl transfer rather than a hydrolysis reaction. in the present study, we describe the x-ray crystal structure of ... | 2005 | 15352873 |
| identification of extracellular enzyme producing thermophilic bacilli from balcova (agamemnon) geothermal site by its rdna rflp. | molecular characterization of extracellular enzyme producing thermophilic bacilli from balcova geothermal site. | 2004 | 15357731 |
| wide-range distribution of insertion sequences identified in b. halodurans among bacilli and a new transposon disseminated in alkaliphilic and thermophilic bacilli. | all of the insertion sequences (iss) except for is663 and a group ii intron identified in the alkaliphilic bacillus halodurans c-125 genome were also detected in nine other strains of the same species by pcr and southern blot analysis. the transposase of is 653 identified in the genomes of the 10 strains of b. halodurans was found to have become the most diversified of all iss identified in the genomes of 10 strains. a new is element designated is661 belonging to the is1380 family with inverted ... | 2004 | 15368891 |
| occurrence of antibiotic residues in milk from manchega ewe dairy farms. | ewe milk samples from different ovine dairy farms from the castilla-la mancha region of spain were collected from bulk tanks to estimate the occurrence of antibiotic residues in raw and heated (82 degrees c, 10 min) milk by the delvotest sp test. the month of collection, somatic cell counts, and bacteriology were analyzed and examined by means of a logistic regression model. the screening of a total of 2686 raw milk samples showed 1.7% "positive" and 2.1% "doubtful" results, which decreased afte ... | 2004 | 15377591 |
| enzymes: by chance, or by design? | | 2004 | 15385982 |
| a rapd-based survey of thermophilic bacilli in milk powders from different countries. | twenty-eight milk powders from 18 different countries were examined for the number and type of contaminating thermophilic bacilli. of 742 isolates examined, 96.8% were assigned to the same strains of bacilli as previously found in new zealand powders. the dominant isolate was anoxybacillus flavithermus strain c followed by bacillus licheniformis strain f. the former was also prevalent in new zealand powders and the results demonstrate that a. flavithermus represents a widespread contaminant, see ... | 2004 | 15454316 |
| effect of dimer dissociation on activity and thermostability of the alpha-glucuronidase from geobacillus stearothermophilus: dissecting the different oligomeric forms of family 67 glycoside hydrolases. | the oligomeric organization of enzymes plays an important role in many biological processes, such as allosteric regulation, conformational stability and thermal stability. alpha-glucuronidases are family 67 glycosidases that cleave the alpha-1,2-glycosidic bond between 4-o-methyl-d-glucuronic acid and xylose units as part of an array of hemicellulose-hydrolyzing enzymes. currently, two crystal structures of alpha-glucuronidases are available, those from geobacillus stearothermophilus (agua) and ... | 2004 | 15466046 |
| structure of the topoisomerase iv c-terminal domain: a broken beta-propeller implies a role as geometry facilitator in catalysis. | bacteria possess two closely related yet functionally distinct essential type iia topoisomerases (topos). dna gyrase supports replication and transcription with its unique supercoiling activity, whereas topo iv preferentially relaxes (+) supercoils and is a decatenating enzyme required for chromosome segregation. here we report the crystal structure of the c-terminal domain of topo iv parc subunit (parc-ctd) from bacillus stearothermophilus and provide a structure-based explanation for how topo ... | 2004 | 15466871 |
| amelioration in secretion of hyperthermostable and ca2+ -independent alpha-amylase of geobacillus thermoleovorans by some polyamines and their biosynthesis inhibitor methylglyoxal-bis-guanylhydrazone. | effect of polyamines and their biosynthesis inhibitors on the production of hyperthermostable and ca2+ -independent alpha-amylase by geobacillus thermoleovorans mtcc 4220. | 2004 | 15479417 |
| isolation and characterization of a cellulolytic geobacillus thermoleovorans t4 strain from sugar refinery wastewater. | a novel, cellulolytic, bacterial thermophilic strain, t4, was isolated from sugar refinery wastewater in southern taiwan. this isolate, a gram-negative, motile, aerobically growing sporulating rod, can secrete thermostable endocellulase (endo-1,4-beta-d-glucanase, ec 3.2.1.4) and hydrolyze carboxymethylcellulose (cmc), phosphoric acid-swollen cellulose, avicel, filter paper, and salicin. when strain t4 was grown in cmc medium, the cellulolytic enzyme activity in culture supernatants was stable u ... | 2004 | 15480864 |
| gene cloning and biochemical characterizations of thermostable ribonuclease hiii from bacillus stearothermophilus. | the gene encoding rnase hiii from the thermophilic bacterium bacillus stearothermophilus was cloned and overexpressed in escherichia coli, and the recombinant protein (bst-rnase hiii) was purified and biochemically characterized. bst-rnase hiii is a monomeric protein with 310 amino acid residues, and shows an amino acid sequence identity of 47.1% with b. subtilis rnase hiii (bsu-rnase hiii). the enzymatic properties of bst-rnase hiii, such as ph optimum, metal ion requirement, and cleavage mode ... | 2004 | 15502360 |
| biochemistry. how active sites communicate in thiamine enzymes. | | 2004 | 15514144 |
| a molecular switch and proton wire synchronize the active sites in thiamine enzymes. | thiamine diphosphate (thdp) is used as a cofactor in many key metabolic enzymes. we present evidence that the thdps in the two active sites of the e1 (ec 1.2.4.1) component of the pyruvate dehydrogenase complex communicate over a distance of 20 angstroms by reversibly shuttling a proton through an acidic tunnel in the protein. this "proton wire" permits the co-factors to serve reciprocally as general acid/base in catalysis and to switch the conformation of crucial active-site peptide loops. this ... | 2004 | 15514159 |
| in vitro enzymatic modification of puerarin to puerarin glycosides by maltogenic amylase. | puerarin (daidzein 8-c-glucoside), the most abundant isoflavone in puerariae radix, is prescribed to treat coronary heart disease, cardiac infarction, problems in ocular blood flow, sudden deafness, and alcoholism. however, puerarin cannot be given by injection due to its low solubility in water. to increase its solubility, puerarin was transglycosylated using various enzymes. bacillus stearothermophilus maltogenic amylase (bsma) was the most effective transferase used compared with thermotoga m ... | 2004 | 15542087 |
| evidence for increased local flexibility in psychrophilic alcohol dehydrogenase relative to its thermophilic homologue. | the psychrophilic alcohol dehydrogenase (psadh) cloned from antarctic moraxella sp. tae123 exhibits distinctive catalytic parameters in relation to the homologous thermophilic alcohol dehydrogenase (htadh) from bacillus stearothermophilus lld-r. amide hydrogen-deuterium (h/d) exchange studies using fourier-transformed infrared (ftir) spectroscopy and mass spectrometry (ms) were conducted to investigate whether the differences are caused by variation in either global or regional protein flexibili ... | 2004 | 15544338 |
| geobacillus lituanicus sp. nov. | obligately thermophilic, aerobic, proteolytic, endospore-forming strain n-3(t) was isolated from a high-temperature oilfield in lithuania. 16s rrna gene sequence analysis placed this strain in genetic group 5 of the endospore formers. geobacillus thermoleovorans appeared to be the closest phylogenetic neighbour (99.4 % sequence similarity). the g+c content of strain n-3(t) was 52.5 mol% and matched the range established for the genus geobacillus. studies of dna-dna relatedness and morphological ... | 2004 | 15545423 |
| geobacillus gargensis sp. nov., a novel thermophile from a hot spring, and the reclassification of bacillus vulcani as geobacillus vulcani comb. nov. | a novel thermophilic spore-forming strain, ga(t), was isolated from the garga hot spring located in the northern part of the transbaikal region (russia). strain ga(t) was found to be an aerobic, gram-positive, rod-shaped, thermophilic (optimum growth temperature is 60-65 degrees c), chemo-organotrophic bacterium that grows on various sugars, carboxylic acids and hydrocarbons. the g+c content of its dna is 52.9 mol%. the 16s rrna gene sequence similarity data show that strain ga(t) is closely rel ... | 2004 | 15545427 |
| geobacillus debilis sp. nov., a novel obligately thermophilic bacterium isolated from a cool soil environment, and reassignment of bacillus pallidus to geobacillus pallidus comb. nov. | several aerobic, motile, rod-shaped, thermophilic, spore-forming geobacillus bacteria predominantly giving a gram-positive staining reaction were isolated from a cool soil environment in northern ireland and taxonomically investigated. two isolates, f10 and tf(t), showed low 16s rrna gene sequence similarity to recognized members of the genus geobacillus. phylogenetic tree investigation using neighbour-joining, maximum-likelihood and parsimony methods indicated that strains f10 and tf(t) represe ... | 2004 | 15545458 |
| classification of isolates from locations in austria and yellowstone national park as geobacillus tepidamans sp. nov. | two moderately thermophilic, gram-positive, spore-forming bacteria were isolated from different geographical locations and sources; strain gs5-97(t) from a beet sugar factory in leopoldsdorf, lower austria, and strain ynp10 from a geothermally heated soil, yellowstone national park, usa. the sequences of their 16s rrna genes were found to be 99.8% identical, and dna-dna hybridization experiments revealed that strains gs5-97(t) and ynp10 share 89.9 mol% similarity to each other, but only 34.3 and ... | 2004 | 15545484 |
| description of heterotrophic bacteria occurring in paper mills and paper products. | to isolate aerobic mesophilic bacilli and thermophilic bacteria from different paper mill samples and to evaluate their potential harmfulness. | 2004 | 15546414 |
| structure of a high fidelity dna polymerase bound to a benzo[a]pyrene adduct that blocks replication. | of the carcinogens to which humans are most frequently exposed, the polycyclic aromatic hydrocarbon benzo[a]pyrene (bp) is one of the most ubiquitous. bp is a byproduct of grilled foods and tobacco and fuel combustion and has long been linked to various human cancers, particularly lung and skin. bp is metabolized to diol epoxides that covalently modify dna bases to form bulky adducts that block dna synthesis by replicative or high fidelity dna polymerases. here we present the structure of a high ... | 2005 | 15548515 |
| a group ii intron-type open reading frame from the thermophile bacillus (geobacillus) stearothermophilus encodes a heat-stable reverse transcriptase. | the production of a stable cdna copy of an unstable rna molecule by reverse transcription is a widely used and essential technology for many important applications, such as the construction of gene libraries, production of dna probes, and analysis of gene expression by reverse transcriptase pcr (rt-pcr). however, the synthesis of full-length cdnas is frequently inefficient, because the rt commonly used often produces truncated cdnas. synthesizing cdna at higher temperatures, on the other hand, c ... | 2004 | 15574910 |
| thermoadaptation trait revealed by the genome sequence of thermophilic geobacillus kaustophilus. | we present herein the first complete genome sequence of a thermophilic bacillus-related species, geobacillus kaustophilus hta426, which is composed of a 3.54 mb chromosome and a 47.9 kb plasmid, along with a comparative analysis with five other mesophilic bacillar genomes. upon orthologous grouping of the six bacillar sequenced genomes, it was found that 1257 common orthologous groups composed of 1308 genes (37%) are shared by all the bacilli, whereas 839 genes (24%) in the g.kaustophilus genome ... | 2004 | 15576355 |
| template-free primer-independent dna synthesis by bacterial dna polymerases i using the dnab protein from escherichia coli. | | 2004 | 15584503 |
| effect of digestion temperature and ph on treatment efficiency and evolution of volatile fatty acids during thermophilic aerobic digestion of model high strength agricultural waste. | thermophilic aerobic digestion (tad) of a model agricultural waste, potato peel slurry, at soluble chemical oxygen demand (cod) load equivalent to approximately 8.0 gl(-1), was carried out under batch conditions at 0.5 vvm aeration rate. digestions were carried out at temperatures of 45, 50, 55, 60 and 65 degrees c (or left unregulated) without ph control to study the effect of digestion temperatures on tad. the effects of digestion ph on the process were studied at ph 6.0, 7.0, 8.0, 9.0 and 9.5 ... | 2005 | 15588773 |
| development of a rapid detection and enumeration method for thermophilic bacilli in milk powders. | thermophilic strains of geobacillus, anoxybacillus and bacillus that are able to grow at 55 degrees c and above are recognized as commonly occurring contaminants during the production of milk powders. in particular, anoxybacillus flavithermus strain c and bacillus licheniformis strain f are often the most prevalent. we describe here the development of a taqman-based real-time-pcr assay using a small amplicon of the ribosomal 16s rrna gene for the selective and quantitative detection of thermophi ... | 2005 | 15590090 |
| new recombinant vaccines based on the use of prokaryotic antigen-display systems. | a major challenge in vaccine design has been to identify antigen presentation systems that elicit strong t- and b-cell responses. in the authors' laboratory, two new delivery vehicles derived from nonpathogenic prokaryotic organisms were recently designed and investigated. conserved antigenic determinants were inserted into the n-terminal region of the major pviii coat protein of bacteriophage fd virions or on the surface of an icosahedral scaffold formed by the acyltransferase component (e2 pro ... | 2004 | 15606352 |
| monitoring of steam sterilization process by biologic indicators--a necessary surveillance tool. | | 2004 | 15609450 |
| the three s-layer-like homology motifs of the s-layer protein sbpa of bacillus sphaericus ccm 2177 are not sufficient for binding to the pyruvylated secondary cell wall polymer. | the s-layer protein sbpa of bacillus sphaericus ccm 2177 recognizes a pyruvylated secondary cell wall polymer (scwp) as anchoring structure to the peptidoglycan-containing layer. data analysis from surface plasmon resonance (spr) spectroscopy revealed the existence of three different binding sites with high, medium and low affinity for rsbpa on scwp immobilized to the sensor chip. the shortest c-terminal truncation with specific affinity to scwp was rsbpa(31-318). surprisingly, rsbpa(31-202) com ... | 2005 | 15612928 |
| protein-based biosensors for diabetic patients. | in this article we show the recent progress in the field of glucose sensing based on the utilization of enzymes and proteins as probes for stable and non-consuming fluorescence biosensors. we developed a new methodology for glucose sensing using inactive forms of enzymes such as the glucose oxidase from aspergillus niger, the glucose dehydrogenase from the thermophilic microorganism thermoplasma acidophilum, and the glucokinase from the thermophilic eubacterium bacillus stearothermophilus. gluco ... | 2004 | 15617257 |
| fluorescence glucose detection: advances toward the ideal in vivo biosensor. | the importance of glucose monitoring for in vivo as well as for ex vivo applications has driven a vast number of scientific groups to pursue the development of an advanced glucose sensor. such a sensor must be robust, versatile, and capable of the long-term, accurate and reproducible detection of glucose levels in various testing media. among the different configurations and signal transduction mechanisms used, fluorescence-based glucose sensors constitute a growing class of glucose sensors repr ... | 2004 | 15617261 |
| possible structure and function of the extra c-terminal sequence of pyruvate kinase from bacillus stearothermophilus. | the pyruvate kinases from genus bacillus and a few other bacteria have an extra c-terminal sequence with a phosphoenolpyruvate binding motif composed of about 110 amino acids. to elucidate the possible structure and function of this sequence, the enzyme lacking the sequence was prepared and characterized. the n-terminal sequences of the peptides, which were found only in the lysylendopeptidase digest of the wild enzyme and not in that of the truncated enzyme, were determined. all the determined ... | 2004 | 15625316 |
| biochemical characterization and identification of the catalytic residues of a family 43 beta-d-xylosidase from geobacillus stearothermophilus t-6. | beta-d-xylosidases are hemilcellulases that hydrolyze short xylooligosaccharides into xylose units. here, we describe the characterization and kinetic analysis of a family 43 beta-xylosidase from geobacillus stearothermophilus t-6 (xynb3). enzymes in this family use an inverting single-displacement mechanism with two conserved carboxylic acids, a general acid, and a general base. xynb3 was most active at 65 degrees c and ph 6.5, with clear preference to xylose-based substrates. products analysis ... | 2005 | 15628881 |
| interaction of the e2 and e3 components of the pyruvate dehydrogenase multienzyme complex of bacillus stearothermophilus. use of a truncated protein domain in nmr spectroscopy. | a (15)n-labelled peripheral-subunit binding domain (psbd) of the dihydrolipoyl acetyltransferase (e2p) and the dimer of a solubilized interface domain (e3int) derived from the dihydrolipoyl dehydrogenase (e3) were used to investigate the basis of the interaction of e2p with e3 in the assembly of the pyruvate dehydrogenase multienzyme complex of bacillus stearothermophilus. thirteen of the 55 amino acids in the psbd show significant changes in either or both of the (15)n and (1)h amide chemical s ... | 2005 | 15634348 |
| distinct metal dependence for catalytic and structural functions in the l-arabinose isomerases from the mesophilic bacillus halodurans and the thermophilic geobacillus stearothermophilus. | l-arabinose isomerase (ai) catalyzes the isomerization of l-arabinose to l-ribulose. it can also convert d-galactose to d-tagatose at elevated temperatures in the presence of divalent metal ions. the araa genes, encoding ai, from the mesophilic bacterium bacillus halodurans and the thermophilic geobacillus stearothermophilus were cloned and overexpressed in escherichia coli, and the recombinant enzymes were purified to homogeneity. the purified enzymes are homotetramers with a molecular mass of ... | 2005 | 15639234 |
| the propeptide is not required to produce catalytically active neutral protease from bacillus stearothermophilus. | the thermolysin-like neutral protease from bacillus stearothermophilus (tlp-ste) is usually produced extracellularly in bacillus subtilis, where it is expressed as preproenzyme and subsequently processed in an autocatalytic, intramolecular process. to create the basis for the production of inactive mutants of tlp-ste, which cannot be processed in b. subtilis, we studied the expression of tlp-ste and its propeptide in cis and in trans in escherichia coli. in contrast to thermolysin, subtilisin an ... | 2005 | 15642473 |
| gene replacement of adenylate kinase in the gram-positive thermophile geobacillus stearothermophilus disrupts adenine nucleotide homeostasis and reduces cell viability. | thermophilic bacteria are of great value for industry and research communities. unfortunately, the cellular processes and mechanisms of these organisms remain largely understudied. in the present study, we investigate how the inactivation of adenylate kinase (ak) affects the adenine nucleotide homeostasis of a gram-positive moderate thermophile, geobacillus stearothermophilus strain nub3621-r. ak plays a major role in the adenine nucleotide homeostasis of living cells and has been shown to be es ... | 2005 | 15647886 |
| evaluation of hydrogen peroxide vapour as a method for the decontamination of surfaces contaminated with clostridium botulinum spores. | the aim of this study was to evaluate the efficacy of hydrogen peroxide vapour (hpv) against spores of clostridium botulinum, for use as a method for decontaminating environments where this pathogen has been handled. spores were dried onto stainless steel slides and exposed to hpv in a sealed glovebox enclosure, transferred to a quenching agent at timed intervals during the exposure period, before survivors were cultured and enumerated. d-values were calculated from graphs of log10 survivors plo ... | 2005 | 15649542 |
| gene cloning, functional expression and secretion of the s-layer protein sgse from geobacillus stearothermophilus nrs 2004/3a in lactococcus lactis. | the ~93-kda surface layer protein sgse of geobacillus stearothermophilus nrs 2004/3a forms a regular crystalline array providing a nanopatterned matrix for the future display of biologically relevant molecules. lactococcus lactis nz9000 was established as a safe expression host for the controlled targeted production of sgse based on the broad host-range plasmid pnz124sph, into which the nisa promoter was introduced. sgse devoid of its signal peptide-encoding sequence was cloned into the new vect ... | 2005 | 15675069 |
| geobacillus jurassicus sp. nov., a new thermophilic bacterium isolated from a high-temperature petroleum reservoir, and the validation of the geobacillus species. | four thermophilic, spore-forming bacterial strains, ds1(t), ds2, 46 and 49, were isolated from the high-temperature dagang oilfield, located in china. the strains were identified by using the polyphasic taxonomy approach. these were aerobic, gram-positive, rod-shaped, moderately thermophilic (with an optimum growth temperature of 60-65 degrees c), chemoorganotrophic bacteria capable of growing on various sugars, carboxylic acids and crude oil. two strains, ds1(t) and ds2, were capable of growing ... | 2005 | 15709364 |
| a thermodynamic study of mesophilic, thermophilic, and hyperthermophilic l-arabinose isomerases: the effects of divalent metal ions on protein stability at elevated temperatures. | to gain insight into the structural stability of homologous homo-tetrameric l-arabinose isomerases (ai), we have examined the isothermal guanidine hydrochloride (gdnhcl)-induced unfolding of ais from mesophilic bacillus halodurans (bhai), thermophilic geobacillus stearothermophilus (gsai), and hyperthermophilic thermotoga maritima (tmai) using circular dichroism spectroscopy. the gdnhcl-induced unfolding of the ais can be well described by a two-state reaction between native tetramers and unfold ... | 2005 | 15710423 |
| aglycon specificity profiling of alpha-glucosidases using synthetic probes. | we designed and synthesized hydrogen bond based probes 1-8 with the exception of known glycosidase inhibition mechanisms, and aglycon specificity of 11 different sources of alpha-glucosidases were investigated using their probes. probe 4 (2,6-anhydro-1-deoxy-1-[(1-oxopentyl-5-hydroxy)amino]-d-glycero-d-ido-heptitol) showed a potent inhibition of s. cerevisiae alpha-glucosidase among all alpha-glucosidases. probe 4 was found to be a competitive inhibitor for s. cerevisiae alpha-glucosidase with k ... | 2005 | 15713413 |
| the hpr proteins from the thermophile bacillus stearothermophilus can form domain-swapped dimers. | the study of proteins from extremophilic organisms continues to generate interest in the field of protein folding because paradigms explaining the enhanced stability of these proteins still elude us and such studies have the potential to further our knowledge of the forces stabilizing proteins. we have undertaken such a study with our model protein hpr from a mesophile, bacillus subtilis, and a thermophile, bacillus stearothermophilus. we report here the high-resolution structures of the wild-ty ... | 2004 | 15713472 |
| misfolded forms of glyceraldehyde-3-phosphate dehydrogenase interact with groel and inhibit chaperonin-assisted folding of the wild-type enzyme. | we studied the interaction of chaperonin groel with different misfolded forms of tetrameric phosphorylating glyceraldehyde-3-phosphate dehydrogenase (gapdh): (1) gapdh from rabbit muscles with all sh-groups modified by 5,5'-dithiobis(2-nitrobenzoate); (2) o-r-type dimers of mutant gapdh from bacillus stearothermophilus with amino acid substitutions y283v, d282g, and y283v/w84f, and (3) o-p-type dimers of mutant gapdh from b. stearothermophilus with amino acid substitutions y46g/s48g and y46g/r52 ... | 2005 | 15741339 |
| comparison of low-temperature hydrogen peroxide gas plasma sterilization for endoscopes using various sterrad models. | this study compared the effectiveness of sterilizing four types of endoscope using different models of the sterrad system (sterrad 50, 100, 100s and 200). sterilization levels meeting international requirements were attained in all cases with carriers inoculated with geobacillus stearothermophilus spores. the endoscopes were tested in half cycles ('overkill'). this is the first study to compare the sterrad models marketed to date in terms of effective sterilization of endoscopes with narrow lume ... | 2005 | 15749314 |
| mutagenesis of the active site lysine 221 of the pyruvate kinase from bacillus stearothermophilus. | lysine 221 of the pyruvate kinase from bacillus stearothermophilus was mutated to arginine, leucine, asparatic acid and cysteine. all the mutated enzymes were 10(4) to 10(5) times less active than the wild-type enzyme. the cysteine-free enzyme c9s/c268s, and the enzyme c9s/c268s/k221c, which possessed a unique sulfhydryl group at position 221, were prepared. the former had comparable activity to the wild-type enzyme and the latter was 10(4) times less active. these enzymes were denatured and ren ... | 2005 | 15749828 |
| an engineered disulfide bridge mimics the effect of calcium to protect neutral protease against local unfolding. | the extreme thermal stabilization achieved by the introduction of a disulfide bond (g8c/n60c) into the cysteine-free wild-type-like mutant (pwt) of the neutral protease from bacillus stearothermophilus[mansfeld j, vriend g, dijkstra bw, veltman or, van den burg b, venema g, ulbrich-hofmann r & eijsink vg (1997) j biol chem272, 11152-11156] was attributed to the fixation of the loop region 56-69. in this study, the role of calcium ions in the guanidine hydrochloride (gdnhcl)-induced unfolding and ... | 2005 | 15752367 |
| examination of mgatp binding in a tryptophan-shift mutant of phosphofructokinase from bacillus stearothermophilus. | a tryptophan-shift variant of bacillus stearothermophilus phosphofructokinase (bspfk), w179f/f76w, was constructed to evaluate the binding and allosteric characteristics associated with mgatp. w179f/f76w bspfk has a specific activity of 77+/-1 u/mg at ph 7 and 25 degrees c, which is a 35% decrease compared to the wild-type enzyme. the k(m) for mgatp increases from 43+/-3 microm for wild-type bspfk to 160+/-7 microm in the variant. binding and allosteric interaction between fru-6-p and pep for th ... | 2005 | 15752723 |
| identification of a gene cluster encoding an arginine atp-binding-cassette transporter in the genome of the thermophilic gram-positive bacterium geobacillus stearothermophilus strain dsmz 13240. | a single gene cluster encoding components of a putative atp-binding cassette (abc) transporter for basic amino acids was identified in the incomplete genome sequence of the thermophilic gram-positive bacterium geobacillus stearothermophilus by blast searches. the cluster comprises three genes, and these were amplified from chromosomal dna of g. stearothermophilus, ligated into plasmid vectors and expressed in escherichia coli. the purified solute-binding protein (designated artj) was demonstrate ... | 2005 | 15758229 |
| the dependence of the sporicidal effects on the power and pressure of rf-generated plasma processes. | the sporicidal effect of 20 different radio-frequency plasma processes produced by combining five different gas mixtures [o(2), ar/h(2) (50/50%), ar/h(2) (5/95%), o(2)/h(2) (50/50%), o(2)/h(2) (95/5%)] with four power/pressure settings were tested. sporicidal effects of oxygen-containing plasmas were dependent on power at low pressure settings but not at high pressure settings. in the absence of oxygen no power dependency was observed at either high or low pressure settings. survivor curves obta ... | 2005 | 15765503 |
| simulation and experiment at high temperatures: ultrafast folding of a thermophilic protein by nucleation-condensation. | we used phi-value analysis to characterise the transition state for folding of a thermophilic protein at the relatively high temperature of 325 k. phif values for the folding of the three-helix bundle, peripheral subunit binding domain from bacillus stearothermophilus (e3bd) were determined by temperature-jump experiments in the absence of chemical denaturants. e3bd folded in microseconds through a highly diffuse transition state. excellent agreement was observed between experiment and the resul ... | 2005 | 15769475 |
| n-acetylmuramic acid as capping element of alpha-d-fucose-containing s-layer glycoprotein glycans from geobacillus tepidamans gs5-97t. | geobacillus tepidamans gs5-97(t) is a novel gram-positive, moderately thermophilic bacterial species that is covered by a glycosylated surface layer (s-layer) protein. the isolated and purified s-layer glycoprotein sgta was ultrastructurally and chemically investigated and showed several novel properties. by sds-page, sgta was separated into four distinct bands in an apparent molecular mass range of 106-166 kda. the three high molecular mass bands gave a positive periodic acid-schiff staining re ... | 2005 | 15781455 |
| studies on bacillus stearothermophilus. part iv. influence of enhancers on biotransformation of testosterone. | the impact of chemical enhancers on the biotransformation of testosterone has been exploited. application of crude cell concentrates to produce bacillus stearothermophilus-mediated bioconversion of testosterone at 65 degrees c for 72 h has been examined. after incubation, the xenobiotic substrate was added to the concentrated whole cell suspensions. the enhancer molecules were included in the whole cell suspension. the resultant products, after extraction into an organic solvent, were purified b ... | 2005 | 15784287 |
| evaluating the formulae for integrated lethality in ethylene oxide sterilization using six different endospore forming strains of bacteria, and comparisons of integrated lethality for ethylene oxide and steam systems. | bacterial endospores from six different species of bacteria were exposed to a spectrum of ethylene oxide (eto) sterilizing conditions. temperature was varied from 40 to 60 degrees c and the ethylene oxide concentration was varied from 300 to 750 mg/l. relative humidity was maintained at 60+/-10% rh. the fraction negative procedure was used to determine the d value for each of the test conditions. bacterial species tested included bacillus atrophaeus atcc # 9372, bacillus smithii atcc # 51232, ba ... | 2005 | 15796136 |
| backbone and side-chain 1h, 15n, and 13c assignments for the beta domain of the bacterial cell division protein divib. | | 2005 | 15803402 |
| effect of a y265f mutant on the transamination-based cycloserine inactivation of alanine racemase. | the requirement for d-alanine in the peptidoglycan layer of bacterial cell walls is fulfilled in part by alanine racemase (ec 5.1.1.1), a pyridoxal 5'-phosphate (plp)-assisted enzyme. the enzyme utilizes two antiparallel bases focused at the c(alpha) position and oriented perpendicular to the plp ring to facilitate the equilibration of alanine enantiomers. understanding how this two-base system is utilized and controlled to yield reaction specificity is therefore a potential means for designing ... | 2005 | 15807525 |
| conversion of the tetrameric restriction endonuclease bse634i into a dimer: oligomeric structure-stability-function correlations. | the bse634i restriction endonuclease is a tetramer and belongs to the type iif subtype of restriction enzymes. it requires two recognition sites for its optimal activity and cleaves plasmid dna with two sites much faster than a single-site dna. we show that disruption of the tetramerisation interface of bse634i by site-directed mutagenesis converts the tetrameric enzyme into a dimer. dimeric w228a mutant cleaves plasmid dna containing one or two sites with the same efficiency as the tetramer cle ... | 2005 | 15811381 |
| surface salt bridges modulate the dna site size of bacterial histone-like hu proteins. | bacterial histone-like dna-binding proteins are best known for their role in compacting the genomic dna. of these proteins, hu is ubiquitous and highly conserved across the eubacterial kingdom. using the hbsu (bacillus subtilis-encoded hu homologue) as a model, we explore here the molecular basis for the ability of some hu homologues to engage a longer approx. 35 bp dna site as opposed to the much shorter sites reported for other homologues. using electrophoretic mobility-shift assays, we show t ... | 2005 | 15845027 |
| enzymatic synthesis of a new inhibitor of alpha-amylases: acarviosinyl-isomaltosyl-spiro-thiohydantoin. | synthesis of acarviosinyl-isomaltosyl-spiro-thiohydantoin in yields up to 20%, has been achieved by bacillus stearothermophilus maltogenic amylase (bsma). bsma is capable of transferring the acarviosine-glucose residue from an acarbose donor onto glucopyranosylidene-spiro-thiohydantoin. reactions were followed using hplc and maldi-tof ms. 1h and 13c nmr studies revealed that the enzyme reserved its stereoselectivity. glycosylation took place mainly at c-6 resulting in alpha-acarviosinyl-(1-->4)- ... | 2005 | 15854600 |
| phluorin-based in vivo assay for hydrolase screening. | phluorin, a ph-sensitive mutant of green fluorescent protein (gfp), acts as a sensor for intracellular ph shifts, triggered by hydrolytic enzymes. this principle was used to develop a phluorin-based in vivo assay for hydrolase screening. the presented assay was evaluated for escherichia coli (e. coli) cells, producing heterologous phluorin and an esterase from geobacillus stearothermophilus which is considered as a model hydrolase. subsequently, the utility of this detection system was also demo ... | 2005 | 15859586 |
| role of lys-226 in the catalytic mechanism of bacillus stearothermophilus serine hydroxymethyltransferase--crystal structure and kinetic studies. | serine hydroxymethyltransferase (shmt), a pyridoxal 5'-phosphate (plp)-dependent enzyme catalyzes the reversible conversion of l-ser and tetrahydropteroylglutamate (h(4)pteglu) to gly and 5,10-methylene tetrahydropteroylglutamate (ch(2)-h(4)pteglu). biochemical and structural studies on this enzyme have implicated several residues in the catalytic mechanism, one of them being the active site lysine, which anchors plp. it has been proposed that this residue is crucial for product expulsion. howev ... | 2005 | 15865438 |
| application of a recn sequence similarity analysis to the identification of species within the bacterial genus geobacillus. | full-length recn and 16s rrna gene sequences were determined for a collection of 68 strains from the thermophilic gram-positive genus geobacillus, members of which have been isolated from geographically and ecologically diverse locations. phylogenetic treeing methods clustered the isolates into nine sequence similarity groups, regardless of which gene was used for analysis. several of these groups corresponded unambiguously to known geobacillus species, whereas others contained two or more type ... | 2005 | 15879251 |
| direct characterization of the folded, unfolded and urea-denatured states of the c-terminal domain of the ribosomal protein l9. | the stability of the isolated c-terminal domain of the ribosomal protein l9 (ctl9) is strongly dependent upon ph. below ph 4.2, the folded and unfolded states are both populated significantly. their interconversion is slow on the nmr chemical shift time-scale and separate, well-resolved resonances from each state are observed. this allows the hydrodynamic properties of both states to be studied under identical conditions by using pulse field gradient nmr experiments. hydrodynamic radii of the fo ... | 2005 | 15890362 |
| a superhelical spiral in the escherichia coli dna gyrase a c-terminal domain imparts unidirectional supercoiling bias. | dna gyrase is unique among type ii topoisomerases in that its dna supercoiling activity is unidirectional. the c-terminal domain of the gyrase a subunit (gyra-ctd) is required for this supercoiling bias. we report here the x-ray structure of the escherichia coli gyra-ctd (protein data bank code 1zi0). the e. coli gyra-ctd adopts a circular-shaped beta-pinwheel fold first seen in the borrelia burgdorferi gyra-ctd. however, whereas the b. burgdorferi gyra-ctd is flat, the e. coli gyra-ctd is spira ... | 2005 | 15897198 |
| cloning and characterization of a carboxylesterase from bacillus coagulans 81-11. | a genomic library of bacillus coagulans strain 81-11 was screened in escherichia coli jm83 for lipolytic activity by using tributyrin agar plates. a 2.4 kb dna fragment was subcloned from a lipolytic-positive clone and completely sequenced. nucleotide sequence analysis predicted a 723 bp open reading frame (orf), designated estc1, encoding a protein of 240 amino acids with an estimated molecular mass of 27,528 da and a pi of 9.15. the deduced amino acid sequence of the estc1 gene exhibited signi ... | 2005 | 15902466 |
| discovery of antagonist peptides against bacterial helicase-primase interaction in b. stearothermophilus by reverse yeast three-hybrid. | developing small-molecule antagonists against protein-protein interactions will provide powerful tools for mechanistic/functional studies and the discovery of new antibacterials. we have developed a reverse yeast three-hybrid approach that allows high-throughput screening for antagonist peptides against essential protein-protein interactions. we have applied our methodology to the essential bacterial helicase-primase interaction in bacillus stearothermophilus and isolated a unique antagonist pep ... | 2005 | 15911380 |
| histidines 345 and 378 of bacillus stearothermophilus leucine aminopeptidase ii are essential for the catalytic activity of the enzyme. | the conserved histidine residues, his-191, his-227, his-345, and his-378, in bacillus stearothermophilus leucine aminopeptidase ii (lapii) were replaced with leucine by site-directed mutagenesis. the overexpressed wild-type and mutant enzymes have been purified by nickel-chelate chromatography and their molecular masses were approximately 44.5 kda. under assay conditions, no lap activity was detected in h345l and h378l. although the km value for h191l increased more than 30% with respect to the ... | 2005 | 15928987 |
| two thimet oligopeptidase-like pz peptidases produced by a collagen-degrading thermophile, geobacillus collagenovorans mo-1. | a collagen-degrading thermophile, geobacillus collagenovorans mo-1, was found to produce two metallopeptidases that hydrolyze the synthetic substrate 4-phenylazobenzyloxycarbonyl-pro-leu-gly-pro-d-arg (pz-plgpr), containing the collagen-specific sequence -gly-pro-x-. the peptidases, named pz peptidases a and b, were purified to homogeneity and confirmed to hydrolyze collagen-derived oligopeptides but not collagen itself, indicating that pz peptidases a and b contribute to collagen degradation in ... | 2005 | 15937176 |
| purification and characterization of hyperthermotolerant leucine aminopeptidase from geobacillus thermoleovorans 47b. | a thermophilic bacterium, which we designated as geobacillus thermoleovorans 47b was isolated from a hot spring in beppu, oita prefecture, japan, on the basis of its ability to grow on bitter peptides as a sole carbon and nitrogen source. the cell-free extract from g. thermoleovorans 47b contained leucine aminopeptidase (lap; ec 3.4.11.10), which was purified 164-fold to homogeneity in seven steps, using ammonium sulfate fractionation followed by the column chromatography using deae-toyopearl, h ... | 2005 | 15937698 |
| the bacterial helicase-primase interaction: a common structural/functional module. | the lack of a high-resolution structure for the bacterial helicase-primase complex and the fragmented structural information for the individual proteins have been hindering our detailed understanding of this crucial binary protein interaction. two new structures for the helicase-interacting domain of the bacterial primases from escherichia coli and bacillus stearothermophilus have recently been solved and both revealed a unique and surprising structural similarity to the amino-terminal domain of ... | 2005 | 15939015 |
| characterization of thermostable lipase from thermophilic geobacillus sp. tw1. | a novel lipase-producing thermophilic strain tw1, assigned to geobacillus sp. tw1 based on 16s rrna sequence, was isolated from a hot spring in china. based on this strain, a lipase gene encoding 417 amino acids was cloned. subsequently, the lipase gene was expressed in escherichia coli and purified as a fusion protein with glutathione s-transferase. the results showed that the recombinant lipase had an activity optimum at 40 degrees c and ph at 7.0-8.0. it was active up to 90 degrees c at ph 7. ... | 2005 | 15939301 |
| alpha-glucosidase from a strain of deep-sea geobacillus: a potential enzyme for the biosynthesis of complex carbohydrates. | an alpha-glucosidase from geobacillus sp. strain hta-462, one of the deepest sea bacteria isolated from the sediment of the mariana trench, was purified to homogeneity and estimated to be a 65-kda protein by sds-page. at low ion strength, the enzyme exists in the homodimeric form (130 kda). it is a thermo- and alkaline-stable enzyme with a half-life of 13.4 h and a maximum hydrolytic activity at 60 degrees c and ph 9.0 in 15 mm glycine-naoh buffer. the enzyme exclusively hydrolyzed alpha-1,4-gly ... | 2005 | 15940457 |
| zinc in lipase l1 from geobacillus stearothermophilus l1 and structural implications on thermal stability. | lipase l1 from geobacillus stearothermophilus l1 contains an unusual extra domain, making a tight intramolecular interaction with the main catalytic domain through a zn2+-binding coordination. to elucidate the role of the zn2+, we disrupted the zn2+-binding site by mutating the zinc-ligand residues (h87a, d61a/h87a, and d61a/h81a/h87a/d238a). the activity vs. temperature profiles of the mutant enzymes showed that the disruption of the zn2+-binding site resulted in a notable decrease in the optim ... | 2005 | 15949807 |
| a comparative study of ethylene oxide gas, hydrogen peroxide gas plasma, and low-temperature steam formaldehyde sterilization. | to compare the efficacies of ethylene oxide gas (eog), hydrogen peroxide gas plasma (plasma), and low-temperature steam formaldehyde (ltsf) sterilization methods. | 2005 | 15954488 |
| does incineration turn infectious waste aseptic? | incineration of infectious waste is considered to be biologically safe. we performed basic experiments to confirm that bacillus spores are killed by incineration in a muffle furnace. biological samples containing 10(6) spores of bacillus stearothermophilus were placed in stainless steel petri dishes and then into hot furnaces. the furnace temperature and duration of incineration were 300 degrees c for 15 min, 300 degrees c for 30 min, 500 degrees c for 15 min, 500 degrees c for 30 min and 1100 d ... | 2005 | 15963601 |
| hyperthermophilic alpha-l: -arabinofuranosidase from thermotoga maritima msb8: molecular cloning, gene expression, and characterization of the recombinant protein. | a putative alpha-l: -arabinofuranosidase (afase) gene belonging to family 51 of glycosyl hydrolases of a hyperthermophilic bacterium thermotoga maritima msb8 was cloned, sequenced, and overexpressed in escherichia coli. the recombinant protein (tm-afase) was purified to apparent homogeneity by heat treatment (80 degrees c, 30 min), followed by hydrophobic interaction, anion-exchange, and gel permeation column chromatography. tm-afase had a molecular mass of 55,284 da on matrix assisted laser des ... | 2005 | 15965714 |
| tet(l)-mediated tetracycline resistance in bovine mannheimia and pasteurella isolates. | tetracycline-resistant mannheimia and pasteurella isolates, which were negative for the tetracycline resistance genes (tet) commonly detected among these bacteria, were investigated for other tet genes present and their location. | 2005 | 15972309 |
| interactions of the n-terminal domain of ribosomal protein l11 with thiostrepton and rrna. | ribosomal protein l11 has two domains: the c-terminal domain (l11-c76) binds rrna, whereas the n-terminal domain (l11-ntd) may variously interact with elongation factor g, the antibiotic thiostrepton, and rrna. to begin to quantitate these interactions, l11 from bacillus stearothermophilus has been overexpressed and its properties compared with those of l11-c76 alone in a fluorescence assay for protein-rrna binding. the assay relies on 2'-amino-butyryl-pyrene-uridine incorporated in a 58-nucleot ... | 2005 | 15972821 |
| identifying and engineering ion pairs in adenylate kinases. insights from molecular dynamics simulations of thermophilic and mesophilic homologues. | molecular dynamics simulations were performed to study thermal stabilization of proteins via electrostatic interactions of ion pairs. dynamic motions of four ion pairs previously proposed to be important in thermal stability of adenylate kinase from the thermophile bacillus stearothermophilus were monitored during the simulation. one of the four ion pairs identified in the crystal structure, lys180-asp114, was not maintained in close contact suggesting that the ion pair does not contribute to th ... | 2005 | 15995248 |
| structures of tryptophanyl-trna synthetase ii from deinococcus radiodurans bound to atp and tryptophan. insight into subunit cooperativity and domain motions linked to catalysis. | an auxiliary tryptophanyl trna synthetase (drtrprs ii) that interacts with nitric-oxide synthase in the radiation-resistant bacterium deinococcus radiodurans charges trna with tryptophan and 4-nitrotryptophan, a specific nitration product of nitric-oxide synthase. crystal structures of drtrprs ii, empty of ligands or bound to either trp or atp, reveal that drtrprs ii has an overall structure similar to standard bacterial trprss but undergoes smaller amplitude motions of the helical trna anti-cod ... | 2005 | 15998643 |
| the binding interface between bacillus stearothermophilus ribosomal protein s15 and its 5'-translational operator mrna. | the bacillus stearothermophilus ribosomal protein s15 (bs15) binds a purine-rich three-helix junction motif in the central domain of 16s ribosomal rna (rrna) as well as a translational operator located in the 5'-untranslated region (5'-utr) of its cognate messenger rna (mrna). an in-frame fusion between the 5'-utr of the bs15 gene and beta-galactosidase (lacz) was prepared, and tested for bs15-dependent translational repression of lacz activity in escherichia coli. the presence of bs15 in trans ... | 2005 | 16005889 |
| a modified consensus approach to mutagenesis inverts the cofactor specificity of bacillus stearothermophilus lactate dehydrogenase. | lactate dehydrogenase from bacillus stearothermophilus is specific for nad+. there have been several attempts to alter the cofactor specificity of this enzyme, but these have yielded enzymes with relatively low activities that still largely prefer nad+. a modified consensus approach was used to create a library of phylogenetically preferred amino acids situated near the cofactor binding site, and variants were screened for their ability to utilize nmn+. a triple mutant (mut31) was discovered tha ... | 2005 | 16012175 |
| the sterility of hospital-prepared soffban bandages. | an evaluation of the sterility of hospital-prepared soffban bandages was undertaken. discs of bacillus stearothermophilus were inserted into the bandage rolls, prior to sterilization in "porous load" autoclaves. the discs were subsequently removed and placed in culture media, with growth of the organism indicating failure of sterilization. it was demonstrated that soffban could not be sterilized reliably using standard hospital autoclave techniques. | 2005 | 16019112 |
| secretion of heterologous proteins in bacillus subtilis can be improved by engineering cell components affecting post-translocational protein folding and degradation. | to explore the potential to enhance secretion of heterologous proteins in bacillus subtilis by engineering cell factors affecting extracytoplasmic protein folding and degradation. | 2005 | 16033468 |
| isolation of uncultivated anaerobic thermophiles from compost by supplementing cell extract of geobacillus toebii in enrichment culture medium. | several researchers have reported that microorganisms can be cultivated only in the presence of other microorganisms. we suggest that a portion of uncultivated microorganisms might be cultivated in the presence of cellular components released from bacteria in their natural environments. in this study, the cell extract of geobacillus toebii was used to enrich uncultivated thermophiles from compost. in the process of enrichment cultures, cell extract supplementation apparently changed the communit ... | 2005 | 16041476 |
| regulation of photosynthetic gapdh dissected by mutants. | glyceraldehyde-3-phosphate dehydrogenase (gapdh) of higher plants catalyzes an nadph-consuming reaction, which is part of the calvin cycle. this reaction is regulated by light via thioredoxins and metabolites, while a minor nadh-dependent activity is constant and constitutive. the major native isozyme is formed by a- and b-subunits in stoichiometric ratio (a2b2, a8b8), but tetramers of recombinant b-subunits (gapb) display similar regulatory features to a2b2-gapdh. the c-terminal extension (cte) ... | 2005 | 16055685 |
| comparative study of tributyltin toxicity on two bacteria of the genus bacillus. | tributyltin is a potent biocide mainly used in marine anti-fouling paints. owing to its widespread distribution in coast areas and its high toxicity to aquatic organisms, the use of this compound is generally restricted and under government regulation. despite of that, it persists in the aquatic environment. organotins used in industry have also been detected in terrestrial environments. the persistence and high lipophilicity explain bioaccumulation. the role of bacteria in recycling organic mat ... | 2005 | 16061343 |